1. Field of the Invention
The present invention relates to a rolling mill stand with at least one manipulator for axially moving the rolls, particularly the work rolls. The rolls are supported and secured in chocks The chocks are guided in the housings of the rolling mill stand so as to be vertically slidable in the direction of the rolling force. The chocks include pushing blocks which guide horizontally in the direction of the roll axes. The manipulators act on the pushing blocks from the operator side.
2. Description of the Related Art
For improving the planeness of the material to be rolled and for a better thickness constancy over the width of the material to be rolled, it is known in the art to slidably support the rolls in the rolling mill stand. For this purpose, adjusting devices are arranged on the so-called operator side of the rolling mill stand. The adjusting devices serve to slide the rolls in horizontal direction. Recent demands made of the quality of the material to be rolled has resulted in displacement distances of increasing length.
German Offenlegungsschrift 24 40 495 discloses a rolling mill stand which includes two work rolls, two intermediate rolls and two back-up rolls as well as a device for the axial displacement of the intermediate roll. In this rolling mill stand, the rolls are supported in chocks. The chocks are mounted in the rolling mill stand housings so as to be slidable in the direction of the rolling force. The intermediate rolls can be axially displaced together with the chocks by means of hydraulic piston-cylinder units which act in the direction of the roll axis. Two axially outwardly projecting arms are provided on one of the chocks of each intermediate roll. The extendable portion of each pistoncylinder unit acts through a connecting member on each of these arms. The two piston-cylinder units are arranged in the rolling mill stand housings laterally next to the respective chock.
This known construction of a manipulator for the rolls of a rolling mill stand enables, if at all, only small displacement distances because large displacements of the rolls would require correspondingly large strokes of the hydraulically acting piston-cylinder unit. This results in the disadvantage that adjusting cylinders of corresponding lengths project into the operator side of the rolling mill stand and reduce the space available for the required exchanges and maintenance of the roll. As a result, the set of rolls would have to be pulled out very far during an exchange of rolls, for example, during sideshifting. This, in turn, would lead to long cylinders for pulling out the rolls or would even require the use of expensive, complicated telescopic cylinders.
It is, therefore, the primary object of the present invention to provide a manipulator for rolls in a rolling mill stand which manipulator is of compact construction and still permits large displacement distances of the rolls and does not disadvantageously reduce the space on the operator side of the rolling mill stand.